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Dr
Peter Elmer
(PRINCETON UNIVERSITY)
23/03/2009, 14:00
Performance of an experiment's simulation, reconstruction and analysis
software is of critical importance to physics competitiveness and making
optimum use of the available budget. In the last 18 months the performance
improvement program in the CMS experiment has produced more than a ten-fold
gain in reconstruction performance alone, a significant reduction in mass
storage system...
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Mr
Giulio Eulisse
(NORTHEASTERN UNIVERSITY OF BOSTON (MA) U.S.A.)
23/03/2009, 14:20
In 2007 the CMS experiment first reported some initial findings on the
impedance mismatch between HEP use of C++ and the current generation
of compilers and CPUs. Since then we have continued our analysis of
the CMS experiment code base, including the external packages we use.
We have found that large amounts of C++ code has been written largely
ignoring any physical reality of the...
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Zachary Marshall
(Caltech, USA & Columbia University, USA)
23/03/2009, 14:40
The ATLAS Simulation validation project is done in two distinct phases. The first one is the computing validation, the second being the physics performance that must be tested and compared to available data. Infrastructure needed at each stage of validation is here described. In ATLAS software development is controlled by nightly builds to check stability and performance. The complete...
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Dr
Thomas Kittelmann
(University of Pittsburgh)
23/03/2009, 15:00
We present an event display for the ATLAS Experiment, called Virtual Point
1 (VP1), designed initially for deployment at point 1 of the LHC, the
location of the ATLAS detector. The Qt/OpenGL based application provides
truthful and interactive 3D representations of both event and non-event
data, and now serves a general-purpose role within the experiment. Thus,
VP1 is used both online (in...
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Kovalskyi Dmytro
(University of California, Santa Barbara)
23/03/2009, 15:20
Fireworks is a CMS event display which is specialized for the physics
studies case. This specialization allows to use a stylized rather
than 3D accurate representation when it's appropriate. Data handling
is greatly simplified by using only reconstructed information and
ideal geometry. Fireworks provides an easy to use interface which
allows a physicist to concentrate only on the data to...
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Oliver Gutsche
(FERMILAB)
23/03/2009, 15:40
The CMS software stack currently consists of more than 2 million lines of
code developed by over 250 authors with a new version being released every
week. CMS has setup a central release validation process for quality
assurance which enables the developers to compare the performance to
previous releases and references.
This process provides the developers with reconstructed datasets of...
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Benedikt Hegner
(CERN)
23/03/2009, 16:30
The re-engineered CMS EDM was presented at CHEP in 2006. Since that time we have gained a lot of operational experience with the chosen model. We will present some of our findings, and attempt to evaluate how well it is meeting its goals. We will discuss some of the new features that have been added since 2006 as well as some of the problems that have been addressed. Also discussed is the...
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Dr
Christopher Jones
(Fermi National Accelerator Laboratory)
23/03/2009, 16:50
The CMS Offline framework stores provenance information within CMS's standard ROOT event data files. The provenance information is used to track how every data product was constructed including what other data products were read in order to do the construction. We will present how the framework gathers the provenance information, the efforts necessary to minimize the space used to store the...
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Giovanni Petrucciani
(SNS & INFN Pisa, CERN)
23/03/2009, 17:10
The CMS Physics Analysis Toolkit (PAT) is presented. The PAT is a high-level analysis layer enabling the development of common analysis efforts across and within Physics Analysis Groups. It aims at fulfilling the needs of most CMS analyses, providing both ease-of-use for the beginner and flexibility for the advanced user. The main PAT concepts are described in detail and some examples from...
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Mr
Philippe Canal
(Fermilab)
23/03/2009, 17:30
One of the main strength of ROOT I/O is its inherent support for schema evolution. Two distinct modes are supported, one manual via a hand coded Streamer function and one fully automatic via the ROOT StreamerInfo. One draw back of the Streamer function is that they are not usable by TTrees in split mode. Until now, the automatic schema evolution mechanism could not be customized by the...
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Dr
Frank Gaede
(DESY IT)
23/03/2009, 17:50
The International Linear Collider is the next large accelerator project in
High Energy Physics.
The ILD Detector Concept is one of three international working groups that
are developing a detector concept for the ILC. It has been created by merging the two
concept studies LDC and GLD in 2007.
ILD uses a modular C++ application framework (Marlin) that is
based on the international...
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Dr
Rainer Mankel
(DESY)
23/03/2009, 18:10
The CMS experiment has performed a comprehensive challenge during May 2008 to test the full scope of offline data handling and analysis activities needed for data taking during the first few weeks of LHC collider operations. It constitutes the first full-scale challenge with large statistics under the conditions expected at the start-up of the LHC, including the expected initial mis-alignments...
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Dr
Georg Weidenspointner
(MPE and MPI-HLL , Munich, Germany)
24/03/2009, 14:00
The production of particle induced X-ray emission (PIXE) resulting from the de-excitation of an ionized atom is an important physical effect that is not yet accurately modelled in Geant4, nor in other general-purpose Monte Carlo systems. Its simulation concerns use cases in various physics domains โ from precision evaluation of spatial energy deposit patterns to material analysis, low...
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Sunanda Banerjee
(Fermilab)
24/03/2009, 14:20
Geant4 provides a number of physics models at intermediate energies (corresponding to incident momenta in the range 1-20 GeV/c). Recently, these models have been validated with existing data from a number of experiments: (a) inclusive proton and neutron production with a variety of beams (pi^-, pi^+, p) at different energies between 1 and 9 GeV/c on a number of nuclear targets (from beryllium...
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Prof.
Leo Piilonen
(Virginia Tech)
24/03/2009, 14:40
We report on the use of the GEANT4E, the track extrapolation feature written
by Pedro Arce, in the analysis of data from Belle experiment: (1) to project
charged tracks from the tracking devices outward to the particle identification
devices, thereby assisting in the identification of the particle type of each
charged track, and (2) to project charged tracks from the tracking...
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Dr
Andreas Salzburger
(DESY & CERN)
24/03/2009, 15:00
With the completion of installation of the ATLAS detector in 2008 and the first days of data taking, the ATLAS collaboration is increasingly focusing on the future upgrade of the ATLAS tracking devices. Radiation damage will make it necessary to replace
the innermost silicon layer (b-layer) after about five years of operation. In addition, with future luminosity upgrades of the LHC machine...
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Dr
Fabio Cossutti
(INFN Trieste)
24/03/2009, 15:20
The CMS simulation has been operational within the new CMS software
framework for more than 3 years. While the description of the
detector, in particular in the forward region, is being completed,
during the last year the emphasis of the work has been put on fine
tuning of the physics output. The existing test beam data for the
different components of the calorimetric system have been...
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Matevz Tadel
(CERN)
24/03/2009, 15:40
HEP computing is approaching the end of an era when simulation parallelisation could be performed simply by running one instance of full simulation per core. The increasing number of cores and appearance of hardware-thread support both pose a severe limitation on memory and memory-bandwidth available to each execution unit.
Typical simulation and reconstruction jobs of AliRoot differ...
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Dr
Cano Ay
(Goettingen)
24/03/2009, 16:30
The Atlas software framework, Athena, is written in C++ using python for job configuration scripts. Physics generators which provide the four-vectors describing the results of LHC collisions are written
in general by third parties and are not part of Athena. These libraries are linked from the LCG Generator Services (GENSER) distribution. Generators are run from within Athena and put the...
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Eduardo Rodrigues Figueiredo
(University of Glasgow),
Manuel Schiller
(Universitรคt Heidelberg)
24/03/2009, 16:50
The LHCb Tracking system consists of four major sub-detectors
and a dedicated magnet. A sequence of algorithms have been
developed to optimally exploit the capability of all tracking
sub-detects. Different configurations of the same algorithms
are used to reconstruct tracks at various stages of the trigger
system, in the standard offline pattern recognition and under
initial conditions...
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Maria Assunta Borgia
(Unknown)
24/03/2009, 17:10
The CMS Silicon Strip Tracker (SST), consisting of more than 10 millions of channels, is organized in about 16,000 detector modules and it is the largest silicon strip tracker ever built for high energy physics experiments. The Data Quality Monitoring system for the Tracker has been developed within the CMS Software framework. More than 100.000 monitorable quantities need to be managed by the...
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Martin Woudstra
(University of Massachusetts)
24/03/2009, 17:30
The Muon Spectrometer for the ATLAS experiment at the LHC is
designed to identify muons with transverse momentum greater
than 3 GeV/c and measure muon momenta with high precision up
to the highest momenta expected at the LHC. The 50-micron sagitta
resolution translates into a transverse momentum resolution of 10%
for muon transverse momenta of 1 TeV/c.
The design resolution requires an...
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Dr
Arno Straessner
(IKTP, TU Dresden), Dr
Matthias Schott
(CERN)
24/03/2009, 17:50
The determination of the ATLAS detector performance in data is
essential for all physics analyses and even more important to
understand the detector during the first data taking period. Hence a
common framework for the performance determination provides a useful
and important tool for various applications.
We report on the implementation of a performance tool with common
software...
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Peter Hristov
(CERN)
24/03/2009, 18:10
The fast feedback from the offline reconstruction is essential for understanding the ALICE detector and the reconstruction software, especially for the first LHC physics studies. For this purpose, ALICE offline reconstruction based on the Parallel ROOT Facility (PROOF) has been designed and developed. The architecture and implementation are briefly described. Particular attention is given to...
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Semen Lebedev
(GSI, Darmstadt / JINR, Dubna)
26/03/2009, 14:00
The Compressed Baryonic Matter (CBM) experiment at the future FAIR facility at Darmstadt will measure dileptons emitted from the hot and dense phase in heavy-ion collisions. In case of an electron measurement, a high purity of identified electrons is required in order to suppress the background. Electron identification in CBM will be performed by a Ring Imaging Cherenkov (RICH) detector and...
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Mrs
Rosi REED
(University of California, Davis)
26/03/2009, 14:20
Vertex finding is an important part of accurately reconstructing events at STAR since many physics parameters, such as transverse momentum for primary particles, depend on the vertex location. Many analysis depend on trigger selection and require an accurate determination of where the interaction that fired the trigger occurred. Here we present two vertex finding methods, the Pile-Up Proof...
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Dr
Kirill Prokofiev
(CERN)
26/03/2009, 14:40
In anticipation of the First LHC data to come, a considerable effort has been devoted to ensure the efficient reconstruction of vertices in the ATLAS detector. This includes the reconstruction of photon conversions, long lived particles, secondary vertices in jets as well as finding and fitting of primary vertices. The implementation of the corresponding algorithms requires a modular design...
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Dr
Andrea Bocci
(Universitร and INFN, Pisa)
26/03/2009, 15:00
The CMS offline software contains a widespread set of algorithms to identify jets originating from the weak decay of b-quarks. Different physical properties of b-hadron decays like lifetime information, secondary vertices and soft leptons are exploited. The variety of selection algorithms range from simple and robust ones, suitable for early data-taking and online environments such as the...
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Mr
Aatos Heikkinen
(Helsinki Institute of Physics)
26/03/2009, 15:20
We report our experience on using ROOT package TMVA for multivariate data analysis, for a
problem of tau tagging in the framework of heavy charged MSSM Higgs boson searches at the LHC.
With a generator level analysis, we investigate how in the ideal case tau tagging could be performed
and hadronic tau decays separated from the hadronic jets of QCD multi-jet background present in...
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Heidi Schellman
(Northwestern University)
26/03/2009, 15:40
The Minerva experiment is a small fully active neutrino experiment which will run in 2010 in the NUMI beamline at Fermilab. The offline computing framework is based on the GAUDI framework. The small Minerva software development team has used the GAUDI code base to produce a functional software environment for simulation of neutrino interactions generated by the GENIE generator and analysis...
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Mr
Alexander Zaytsev
(Budker Institute of Nuclear Physics (BINP))
26/03/2009, 16:30
CMD-3 is the general purpose cryogenic magnetic detector for VEPP-2000 electron-positron collider, which is being commissioned at Budker Institute of Nuclear Physics (BINP, Novosibirsk, Russia). The main aspects of physical program of the experiment are precision measurements of hadronic cross sections, study of known and search for new vector mesons, study of the ppbar a nnbar production...
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Lorenzo Moneta
(on behalf of the ROOT, TMVA, RooFit and RooStats teams)
26/03/2009, 16:50
ROOT, a data analysis framework, provides advanced mathematical and statistical methods needed by the LHC experiments for analyzing their data. In addition, the ROOT distribution include packages such as TMVA, which provides advanced multivariate analysis tools for both classification and regression, and RooFit for performing data modeling and complex fitting.
Recently a large effort is...
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Daniel Kollรกr
(CERN)
26/03/2009, 17:10
The main goals of a typical data anaysis are to compare model predictions with data, to draw conclusions on the validity of the model as a representation of the data, and to extract the possible values of parameters within the context of a model.
The Bayesian Analysis Toolkit, BAT, is a tool developed to evaluate the posterior probability distribution for models and their parameters. It is...
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Andrea Ventura
(INFN Lecce, Universita' degli Studi del Salento, Dipartimento di Fisica, Lecce)
26/03/2009, 17:30
The ATLAS experiment CERN's Large Hadron Collider has been projected and realized for new discoveries in High Energy Physics as well as for precision measurements of Standard Model parameters. To satisfy the limited data acquisition capability, at the LHC project luminosity, the ATLAS trigger system will have to select a very small rate of physically interesting events (~200 Hz) among about 40...
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Mogens Dam
(Niels Bohr Institute)
26/03/2009, 17:50
The ATLAS tau trigger is a challenging component of the online event
selection, as it has to apply a rejection of 10^6 in a very short time
with a typical signal efficiency of 80%. Whilst in the first hardware
level narrow calorimeter jets are selected, in the second and
third software levels candidates are refined on base of simple but
fast (second level) and slow but accurate (third...
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Vasile Mihai Ghete
(Institut fuer Hochenergiephysik (HEPHY))
26/03/2009, 18:10
The CMS L1 Trigger processes the muon and calorimeter detector data using a complex system of custom hardware processors. A bit-level emulation of the trigger data processing has been developed. This is used to validate and monitor the trigger hardware, to simulate the trigger response in monte-carlo data, and for some components, to seed higher-level triggers. The multiple-use cases are...
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